When I'm trying to add an elixir node to a 7.1.1 cluster I see the following error in the UI:

Attention: Prepare join failed. Failed to establish TLS connection to node1.localhost:19001: {bad_record_mac, "TLS client: In state connection at tls_record_1_3.erl:340 generated CLIENT ALERT: Fatal - Bad Record MAC\n decryption_failed"}

That error is generated by client side (7.1.1 node) in this case.

At the same time on the server side ("node-being-added") I see the following error:

=========================NOTICE REPORT=========================

TLS server: In state wait_finished at ssl_gen_statem.erl:736 generated SERVER ALERT: Fatal - Unexpected Message

 - {unexpected_msg,{internal,{change_cipher_spec,<<1>>}}}

Most likely the "Bad Record MAC" error on the client is a consequence of the unexpected_msg error on the server.

It looks like some kind of erlang bug. We didn't see it before so this maybe a new behavior added by the latest erlang upgrade which is currently used in 7.1.2 and elixir now (that's the reason why I added 7.1.2 in the affected versions list).